Electric oil-well heater



(No Model.)

0. W. 8: S. D. ROBISON.

ELECTRIC OIL WELL HEATER.

No. 457,457. Patented Aug. 11, 1891.

INVENTOR.

WITNESSES M WWW- UNITED STATES PATENT OFFICE.

CHARLES WV. ROBISON AND SAMUEL I). ROBISON, OF ALLEGHENY, PENN-SYLVANIA, ASSIGNORS OF TlVO-THIRDS TO ROBERT E. ROBISON AND JOHN G.LUCOCK, OF SAME PLACE, JOHN A. GARTLAN, OE PITTSBURG, AND THOMAS D.\VILLIAMS, OF BELLEVUE, PENNSYLVANIA.

ELECTRIC OIL-WELL HEATER.

SPECIFICATION forming part of Letters Patent No. 457,457, dated August11, 1891.

Application filed February 18, 1891. Serial No. 331,902. (No model.

To all whom, it may concern.-

Be it known that we, CHARLES W.RoB1soN and SAMUEL D. RoBIsoN, ofAllegheny, in the county of Allegheny and State of Pennsylvania, haveinvented a new and useful Improvement in Oil-\Vell Heaters, of which thefollowing is a full, clear, and exact description.

It is well known that oil-wells are apt to become clogged by anaccumulation of paraffine, &c., and to diminish in productiveness. Amethod was discovered and patented by one Roberts foriucreasing theproductiveness of wells by exploding therein a charge ofnitro-glycerine, which acts by loosening the oil-bearing fissures anddispersing the obstruction. A more effective and surer mode of effectingthe desired result and of obtaining from the well its maximum yieldconsists in applying to the oil-bearing strata of the well the heatingaction of an electric current, the effect of which is to melt thefusible obstructing mattersuch as paraffineand by the action of the heatto open and clear the fissures and to permit the oil to flow freely.

Our invention is practiced by inserting into the well an electricalheating-coil or high-resistance conductor, as hereinafter described,and, when it is at the oil-bearing strata, passiug through it a currentof electricity, by which it is heated, so that it may communicate itsheat to the well. The nature of the heating-coil and of the electriccurrent supplied thereto should at least be such that sufficient heat isgenerated to fuse parafline.

The apparatus employed in the practice of our invention may beconstructed in various ways. The form which we have illustrated andwhich we intend to claim specifically is a very convenient form for useand is remarkably efficient in furnishing the electrical action for thepurposes above described.

The apparatus is illustrated in the accompanying drawings, in whichFigure 1 is a side elevation, and Fig. 2 is a vertical axial section,thereof. Figs. 3 and at are cross-sectional plan views on the lines IIIIII and IV IV of Fig. 2.

In the drawings, 2 represents a core by which the electrical conductoris supported, and which is preferably fixed to the upper end of asupporting-frame having upright standards 3, through which theelectrical conductors may be led to the heating-coil, and having a rod4: by which the apparatus may be suspended and let into the well. Theelectrical conductor forming the coil consists of wire of low electricalconductivity (fine German-silver wire will answer the purpose) wrappedaround the core 2, the wire being insulated from the core and eachconvolution being separated or insulated from the adjoiningconvolutions. lVe prefer to use asbestus paper as the insulating medium.In order to protect the heating-coil from damage by abrasion and toprevent it from being short-circuited by contact with the fluids of thewell, we inclose it in a cylindrical casing 5, which at the top fitsupon a head 6, forming part of the frame of the apparatus, and at thelower end is closed by a plug 7, which may be screwed upon the core andis preferably made conical at its lower end. This casing is madewater-tight by packing in a suitable manner. In using the apparatus weattach thereto the electrical conductors, as shown, and by means of asupporting-rope we lower it into the well. Vhen the apparatus hasreached the part of the well containing the parafline, the electriccurrent is supplied by a dynamo or other source of electrical energysituate at the surface of the ground, and passing through the coilrapidly heats the same to a red heat. This heat is communicated byradiation to the casing and by the casing to the oil-well, thus meltingthe clogging matter and clearing and opening the fissures, but withoutdanger of injury to the well, as when an explosive charge is used. Theoperation is thus performed very rapidly and easily.

The shape of the apparatus adapts it to be let into the wellconveniently, and as itis not of undue weight it is easy to manipulate.

The apparatus may be left in the well as long as may be desired, evenduring the pumping or flowing of the well, and the electric current maybe supplied constantly or whenever it is wished to clear the well toincrease its flow, or the apparatus may be in In testimony whereof wehave hereunto set IO serted and removed intermittently. our hands this16th day of February, A. D.

'We clai1n- 1891.

In apparatus for removing paral'line from 5 oil-wells, the combinationof a Water-tight case, an electrical heating-coil therein,asupporting-rod, and two hollow rods containing Vitnesses: the conductorsand attached to the upper \V. B. CORWIN, part of the ease, substantiallyas described. H. M. GORWIN.

CHARLES W. ROBISON. SAMUEL D. ROBISON.

